Preserve expired bans in database

[Alan Beam]

Expected behavior When a ban expires, the ban is marked as no longer valid, but still exists in the database for historical/reporting purposes.

Actual behavior When a ban expires, the ban is removed from the database.

Additional notes This may possibly remove the need for the ban topic. It could also provide the infrastructure needed for a ban history page (for the room, mod, and/or user).

[Alan Beam]

I envision adding an "active" field to the ban table, defaulting to 1 and updating to 0 when the ban expires (instead of deleting it). All ban queries would need to be updated to add "WHERE active = 1".